Influence of tree-shaped fins to enhance thermal storage units

Phase change materials (PCMs) have attracted considerable interest recently due to their remarkable thermal energy storage capabilities for different thermal applications. This would effectively assist in the reduction of CO₂ emissions and encourage the transition to sustainable energy on a global scale. The present study investigates the increase in the thermal efficiency of a shell-and-tube heat exchanger using PCM and a novel arrangement of fins in the form of a tree. The enthalpy-porosity method is used to mimic phase changes under the studied conditions. Moreover, copper nanomaterials are incorporated with the PCM to increase thermal conductivity and speed up the charging process. The influences of various parameters, such as the concentration of nano-additive and the distribution of sub-fins, are investigated. The findings derived from the present model demonstrate that the incorporation of elongated sub-fins in the outer part (far from the inner heating tube) of the PCM unit leads to a noteworthy enhancement in the heat transfer distribution, resulting in a 75.7% reduction in melting time. Adding copper nanomaterials to PCM improves thermal performance. For example, a 6% concentration of nanoparticles leads to a reduction in the melting process by >15% compared to pure PCM.